Eaton Bussmann LPJ-400SP

LPJ-400SP is a Class J time-delay current-limiting fuse from the Low-Peak series by Eaton Bussmann, specifically designed for high-inrush loads such as motors and transformers.

1. Model Definition

LPJ: Low-Peak™ series, Class J, time-delay

400: Rated current 400A

SP: Special Purpose (industrial/motor protection)

SPI: With blown fuse indicator (optional model: LPJ-400SPI)

2. Key Technical Specifications

3. Typical Applications

Motor circuits (MCC), variable frequency drives, transformers

Industrial power distribution, UPS, PV DC circuits

Applications requiring high current limiting, inrush resistance, and nuisance-trip prevention

4. Full Series Models (70–600A)

LPJ-70SP / 80SP / 90SP / 100SP

LPJ-110SP / 125SP / 150SP / 175SP

LPJ-200SP / 225SP / 250SP / 300SP

LPJ-350SP / 400SP / 450SP / 500SP / 600SP

5. Cross-Brand Direct Replacements (400A Class J Time-Delay)

6. Selection & Replacement Notes
7. Class J only: Not interchangeable with Class RK5/H/K; must use Class J fuse holders.
8. Time-delay required: Motor circuits must use LPJ/JTD/AJT time-delay fuses; fast-acting types (JKS) are not suitable.
9. Indicator upgrade: Use LPJ-400SPI for status monitoring.
10. DC applications: Rated at 300V DC, suitable for PV and energy storage DC branches.

Application Scenarios of Eaton Bussmann Fuses

With a full, comprehensive, high-performance product portfolio, Eaton Bussmann fuses cover nearly all electrical protection scenarios from low voltage to high voltage, AC to DC, and industry to new energy, providing reliable overcurrent and short-circuit protection for high-value equipment, critical circuits, and hazardous environments.

1. Industrial Automation & Traditional Manufacturing (Core Scenario)

Designed for industrial equipment including motors, VFDs, and PLCs, with emphasis on inrush resistance, time-delay, and current limiting to prevent nuisance tripping.

Motor Control Centers (MCC) / Motor Circuits

Series: LPJ (Class J), LPN-RK (Class RK5), KTK (Class RK1)

Application: Protect three-phase induction motors, gear reducers, fans, pumps. Time-delay characteristics (≥10s at 500% In for LPJ series) withstand motor starting inrush and prevent tripping during frequent starts/stops.

Variable Frequency Drives & Power Electronics

Series: Fast-acting fuses (FWH, FWX), DIN 43653 square body fuses

Application: Protect VFDs, servo drives, UPS, rectifiers, soft starters. Fast-acting (aR) fuses clear short circuits in microseconds to safeguard expensive semiconductors such as IGBTs.

Industrial Power Distribution & Transformers

Series: NH series, KF series, CM series

Application: Low-voltage switchgear, primary/secondary transformer sides, capacitor banks. Provides overload and short-circuit protection for main and branch circuits with interrupting ratings up to 300kA.

Control Circuits & Precision Circuits

Series: FNQ, FNM (Class CC), MDA, MFD

Application: PLCs, relays, instruments, sensors, control power supplies. Compact size for precise protection of low-current control circuits.

2. New Energy & Green Power (Fastest-Growing Segment)

Engineered for high-voltage DC, high reliability, and explosion protection, covering the entire PV, wind, energy storage, and electric vehicle industrial chain.

Photovoltaic (PV) Systems

Series: PV series, 10×38 PV fuses, GDC series

Application: PV combiner boxes, string circuits, inverter DC sides, central inverters. Compatible with 1000V/1500V DC systems, resistant to temperature cycles and DC arcing.

Energy Storage Systems (ESS) & Power Batteries

Series: EV series, MEV series, 1500V ultra-fast DC fuses

Application: PCS, battery clusters, BMS circuits, containerized ESS. Provides high-voltage DC protection (up to 1500V DC) against thermal runaway and fire risks.

Wind Power Generation

Series: Medium-high voltage fuses, special time-delay fuses

Application: Wind turbine pitch and yaw systems, nacelle cabinets, pad-mount transformers. Adapted to high altitude, strong vibration, and wide temperature ranges.

Electric Vehicles (EV) & Charging Infrastructure

Series: EV, MEGA, AM, FWH

Application:

Vehicles: Main battery pack circuits, on-board chargers (OBC), PDUs, motor controllers.

Charging: DC fast chargers, battery swap stations. Rated up to 1000V DC, covering 10A–1600A.

3. Data Centers & Telecommunications

Ensures 24/7 uninterrupted power supply with high reliability, low power loss, and modular design.

Applications: UPS input/output, precision air conditioning, server power supplies, telecom base stations, IDC PDUs.

Series: KTK, FNQ, LPJ, low-voltage blade fuses

Key Benefits: Strong current limiting, fast fault clearing to prevent single-point failures from spreading; low power loss reduces heat and energy consumption.

4. Petroleum, Chemical, Coal Mining (Hazardous Environments)

Used in flammable gas and dust atmospheres, requiring explosion-proof and flameproof certifications.

Applications: Explosion-proof motors, flameproof VFDs, oilfield pumping units, chemical reactors, underground coal mine equipment.

Series: Explosion-proof certified fuses, Ex d flameproof fuse links

Key Requirements: ATEX, IECEx, CQST certified to prevent ignition of external explosive gases.

5. Rail Transit & Marine

Withstands harsh conditions including strong vibration, high humidity, wide temperatures, and dust.

Rail Transit

Applications: Traction converters, auxiliary power, signaling systems, door controls for high-speed rail and metro.

Series: Fast-acting fuses, special time-delay fuses, EN 50155 certified products

Marine & Offshore

Applications: Marine motors, pumps, compressors, navigation equipment.

Certifications: ABS, DNV, LR marine type approvals, salt-mist and mold resistant.

6. Electric Power Transmission & Distribution (Medium-High Voltage)

Covers full-link protection from power plants to end users.

Applications: Medium-voltage switchgear, transformer protection, capacitor banks, cable feeders, transformer protection.

Series: XRNP (PT protection), XRNM (motor protection), WFN (outdoor)

7. Automotive & Construction Machinery

Conventional Vehicles: ATC/ATO blade fuses, MAXI, MEGA, AMI for lighting, air conditioning, ECUs, starters.

Construction Machinery: Electrical systems for excavators, loaders, cranes, resistant to extreme temperatures and vibration.

8. Quick Selection Guide (By Application)

1. Industrial Motors / MCC / Transformers (For ABB M3JP Explosion-Proof Motors)

Application: Three-phase induction motors, fans, pumps, compressors, transformers

Typical series: LPJ (Class J), LPN-RK (Class RK5)

Features: Time-delay, resistant to motor starting inrush, no nuisance tripping.

2. VFDs, IGBTs, Servos, UPS (Power Electronics Protection)

Application: VFD DC links, rectifiers, inverters, servo drives

Series: FWH, FWX, 170M (square body fast fuses)

≤22kW VFDs: FWX-10A, FWX-20A, FWH-30A

45~75kW VFDs: FWH-60A, FWH-80A

≥160kW high-power drives: 170M series 200A~600A

Features: Ultra-fast aR characteristics, protects expensive semiconductors.

3. PV / Energy Storage / High-Voltage DC (1000V / 1500V DC)

Application: PV combiner boxes, strings, PCS, energy storage battery clusters

Series: PV, EV, GDC, 10×38 PV fuses

PV strings 15A/20A: PV-15A, PV-20A

Combiner boxes 32A: PV-32A

ESS high-voltage DC: EV-315A, EV-400A, EV-500A

Features: DC-optimized, arc-resistant, thermal runaway protection.

4. Control Circuits / PLC / Relays (For Schneider RXM Relays)

Application: Cabinet control circuits, 24V power supplies, instruments, sensors

Series: FNQ, FNM, KTK, MDA

1A~10A control circuits: FNQ-1, FNQ-2, FNQ-5, FNQ-10

Compact terminal block protection: KTK-1, KTK-5

5. Hazardous Explosion-Proof Environments (Petrochemical, Coal Mining, For M3JP Motors)

Application: Ex d flameproof cabinets, Zone 1/2 hazardous areas

Series: LPJ-xxSP with explosion-proof certification, Ex-type fuses

Direct usable models:

LPJ-400SP, LPJ-300SP, LPJ-200SP

Suitable for short-circuit protection in hazardous areas when used with flameproof enclosures.